| Tidal current energy is a green and clean energy source generated by the movement of seawater during the rise and fall of tides.It possesses high power density and strong predictability,making it a subject of broad interest in both academic and industrial sectors.Nevertheless,not all tidal currents offer viable prospects for development,and the portion of tidal current energy that can be feasibly harnessed under present technological,economic,and environmental constraints is referred to as the "Exploitable Tidal Current Energy".With approximately half of China’s theoretical reserves of tidal current energy resources,the Zhoushan Sea area stands out as one of the world’s leading strong tidal zones,offering immense development opportunities.Rational utilization of local tidal current energy resources can supply surrounding areas with clean and sustainable power,yielding significant benefits.Currently,tidal current energy development in the area is in the exploratory phase,and the assessment of the tidal current energy potential is a crucial prerequisite for site selection planning and actual power station deployment.The assessment of tidal current energy potential involves a comprehensive description of the regional tidal current characteristics,development feasibility,and development suitability,as well as an estimation of the available tidal current energy.This study analyzes the critical hydrodynamic factors affecting tidal current energy development and proposes the use of power density and Tidal Stream Exploitability(TSE)index as indicators for evaluating the size and feasibility of tidal current energy.Skewness of flow velocity,absolute difference between the flood direction and standard ebb and flow direction,and effective duration of available development time meeting the development conditions are used as indicators for assessing the asymmetry of flow velocity,rotation of flow direction,and suitability of annual effective development flow time.Different approaches and methods for estimating the tidal current energy potential are also analyzed.The three-dimensional tidal current field in the Zhoushan Sea area required for the evaluation study was established using the MIKE 3 hydrodynamic numerical model,and a generalized model of a turbine array was developed by equivalently adding the effect of drag forces in the model.This was used to analyze the general impact of tidal current energy turbine arrays on the available tidal current energy potential.By analyzing the three-dimensional tidal current characteristics and various evaluation indicators in the Zhoushan Sea area,the potential development areas with superior tidal current energy potential evaluation indicators were identified,and the extractive method and Flux method were used to estimate the available tidal current energy.This assessment study provides a detailed description of the spatial distribution of the tidal current field in the Zhoushan sea area and enriches the evaluation indicators for tidal current energy resource potential.Eight potential areas for tidal current energy development with superior evaluation indicators were identified,and the impact of tidal current energy arrays on flow velocity was analyzed.It was found that the array could lead to an average relative decrease in the flow velocity of tidal current energy development of about 10%.Based on this,the extractive method was used to estimate the tidal current energy potential in these eight areas to be approximately 34 MW,with Guishan Navigation Gate having the most abundant potential for development at approximately 13.59 MW.The estimate of the potential value using the Flux method based on energy flux was relatively higher.This study can provide a reference for tidal current energy development in the Zhoushan sea area. |
PDF Full Text Request